Bionic Commando's ending was ridiculously stupid, was made even worse by the whole "You're wife lives in your legs" twist. I also hated Fable 2's ending cause there was no boss like they set you up to believe, and they also just basically say "You beat Lucien, now go back into the world and keep doing stuff for no reason!", just bummed me out.

Lastly, I thought both Bioshock and Resident Evil 5's ending's were anti-climatic, just both felt rushed and didn't seem to have any really huge inpact to the rest of the story.

Neither of No More Heroes' endings offered any kind of closure, which was especially disappointing considering all of the plot twists/revelations late into the game.

That was the point. Hell, No More Heroes ends with the characters directly referencing the fact that they have too much left to resolve and just want to find an out.

I know, they joke about it and everything, but I would have liked a conclusion, some kind of closure, you know? That being said, the final battle was badass as hell and the post-credits sequence was borderline killer7-level of weird, which I dug. Also, at the beginning of Desperate Struggle, they seem to ignore the last two hours or so of NMH1, as if the plot twists/revelations were never made, further playing with the ending. I get the humour, don't get me wrong.

Legacy of Kain: Soul Reaver. Best game that year, literally ends mid-cutscene with a "To be Continued". Promptly forgiven by LoK: Defiance having one of the best game endings ever. Also, Amy Hennig, you rock.

Any of the famously terrible 8/16-bit era endings. Super Mario Bros 2 is all a dream. Conglaturations. All that stuff.

Spider-Man 2. The PSOne version. Came out in 2001 and the final boss fight happened in the World Trade Center. Obviously got re-cut and they changed the building. The bad part? Well, the main mechanical challenge for the boss fight was to hop from one of the towers to the other to push some switches and the redesign just put a big block between the two towers to make them seem like a single building, so the game ends with your friendly neighborhood Stroll-Man slowly walking back and forth between both spots.

LA Noire's ending really annoyed me. I think the depressing endings can work well, Red Dead Redemption is the perfect example, but with LA Noire it felt like a very forced attempt to be emotional. It was generic, predictable and unsatisfying.

The Skyrim ending comes to mind as the most recent game I "finished" - I mean Oblivion was kinda weak but it was something BUT Skyrim oh man it's just "oh yah ok well good thing that guy is gone too bad it changes nothing and uhh see ya around" and the game just goes. I wish they made a shout that made the credits start rolling across the sky, even that would have been better.